I had the same problem, how are you looking for these internships?
If you're relying on I2MS, unless you have amazing grades it doesn't tend to help much. Too little jobs, too many people using it.
I recently secured my first internship [after 2 years of searching] by cold calling every engineering company i could find the contact details of.
I went on Google Maps and searched for engineering services, then just went through the hits within walking distance to a train station [I'm only on my L's] and took down the contact details of each company, and if they had a website, I also took down a few key points.
Then I went through the list one by one and asked to talk to someone about an internship possibility, usually got the 'send us your resume' spiel.
I got lucky though, and got an interview with the head of the company the next day, by the end of the interview I got the internship outright =]
Good luck, hit up anyone you can for contacts, google maps is your friend, and call as many companies as you can =D